The invention relates to a spinning rotor for an open end rotor spinning machine, particularly a spinning rotor comprising a rotor shaft, a rotor cup having an opening, an inner chamber, a rotor groove, a conically widening slide wall extending from the opening to the rotor groove and a rotor base arranged opposing the opening and designed with a bore, through which the rotor shaft extends at least partially, wherein the rotor shaft is connected by means of a connection element to the rotor cup and the rotor shaft and rotor cup comprise a common rotational axis.
In conjunction with open end rotor spinning machines, a large number of the most varied spinning rotors are known from the patent literature and generally consist of a rotor shaft for mounting the spinning rotor and a rotor cup for producing a thread. Spinning rotors of this type in modern open end spinning machines reach rotational speeds of far above 100,000 min−1. Rotational speeds that are as high as this in total place special demands with regard to imbalance, mounting and stability of spinning rotors of this type. As spinning rotors of this type are heavily stressed, for example as a result of mechanical vibrations, the highest demands are also made of the fastening between the rotor shaft and rotor cup.
Spinning rotors are described, for example, in German Patent Publications DE-OS 28 12 297 or DE 199 10 77 A1, in which the rotor cups are connected to the rotor shaft, in each case via a hub, into which a bore is let. The connection is implemented as a press fit here and is non-releasable.
Furthermore spinning rotors are known from German Patent Publications DE 40 20 518 A1 or DE 103 02 178 A1, in which the rotor cups only have one central bore in the region of the rotor base, in which the rotor shaft is inserted. The rotor shaft is, in this case, equipped with a bearing collar, on which the rotor cup is fixed by a weld connection. A weld connection for fixing a rotor cup on the rotor shaft is also described in German Patent Publication DE 3519 536 A1. In this known device, the rotor cup has an extra thick base. The rotor shaft is fixed to this rotor cup base by means of friction welding.
The aforementioned connections between the rotor cup and rotor shaft in total have the disadvantage that either the connection is relatively heavy, which has a very disadvantageous effect on the acceleration capacity of the spinning rotor, or a change in structure occurs in the components in the course of the attachment of the two rotor parts and this is not unproblematic because of the high rotational speeds of such spinning rotors.